1. Field of the Invention
This invention generally relates to implements for mixing ingredients used in medical offices and particularly in dental offices.
2. Description of Related Art
Procedures formed in medical offices, oftentimes require individuals to combine ingredients in mixtures. In dental offices, for example, personnel commonly mix alginate for making impressions or mix gypsum (i.e., a mixture of water with either plaster or stone) for making positive casts used for fabricating bleaching trays, night guards, diagnostic study models, temporary crowns and the like.
Historically, individuals mix ingredients in a reusable rubber mixing bowl and with a reusable spatula. Rubber bowls and spatulas harbor many disease producing microbes, such as hepatitis B, that without proper precautions can transfer from one patient to another. To avoid cross contamination by such microbes it is necessary to sterilize these items by a complex disinfecting procedure. In accordance with such disinfecting procedures, each implement is washed in warm, soapy water, rinsed and dried. Then an individual sprays the implement with an appropriate disinfectant and allows the implement to air dry for 10 minutes or so before storing the implement for future use. When the implement is to be used again, it must be rinsed under running water to remove any residual disinfectant and then dried. As will be apparent, personnel time makes this an inefficient and expensive process.
A number of approaches have been proposed for simplifying this process and making it less cumbersome by providing disposable means for mixing. One alternative in widespread use comprises a rigid heavy rubber bowl support with a common plastic disposable bowl liner wherein the liner relies upon the bowl support for rigidity during mixing. While the bowl liner is a disposable item, the bowl support is not. Consequently after each use it is necessary to disinfect the bowl support with the same process as previously described. It has been observed that in many situations individuals, for reasons of forgetfulness or lack of time, overlook the requirement for disinfecting the support and merely put it away apparently and erroneously relying upon disposal of the bowl liner as eliminating any possible cross contamination. As will be apparent, this is not a valid assumption. That is, microbes will transfer to the bowl support during use, so these microbes can populate and survive on the bowl support if disinfectant is not applied. Consequently, even with the disposable bowl liner, the above-mentioned disinfecting procedure still is required.
The process for mixing ingredients in bowls and the process for washing and disinfecting reusable bowls, reusable spatulas and bowl supports involve significant repetitive hand-wrist motions that can aggravate symptoms of carpal tunnel syndrome and tendinitis. Moreover, it is often desirable to eliminate any air entrained in a final mixture. Reusable bowls can be used with vibrators to mix gypsum and displace air from the mixture. The elimination of air from a mixture in a bowl liner is less efficient than a reusable bowl because the two-part nature of the bowl support and bowl liner tends to dampen any vibrations that reach the mixture.
As another example, U.S. Pat. No. 5,106,297 to Discko discloses a dental tray used in the preparation of single or multiple component bonding liquids and sealants. The tray has multiple depressions configured to hold a bottle having a cap with the shoulder upside down. This allows a dentist to dispense single or multiple component bonding liquids and sealants. Distinctively shaped wells avoid confusion as to the function of each well. A finger indentation in the side opposite the depressions facilitates holding the tray during lightweight mixing or use.
U.S. Pat. No. 5,240,415 to Haynie discloses a dental bleach system that has separate compartments for fumed silica and for hydrogen peroxide. The fumed silica is provided in a predetermined quantity in a mixing chamber while the hydrogen peroxide is provided as a pre-measured volume in an ampule. The system also includes a spatula for enabling the mixing of the materials in the compartment holding the fumed silica. The package is completed with a sealing cover.
U.S. Pat. No. 5,465,833 to Tarter discloses a dental impression material package. The package includes a bag that encloses dental impression powder and a valve that extends through the bag. Water can be injected through the valve by means of a syringe. After mixing materials within the bag, air can be removed by means of a syringe inserted through the valve. In one embodiment alginate is extruded from the bag through the valve into an impression tray.
Other examples of products adapted for mixing materials for dental or eye care include U.S. Pat. No. 4,852,742 to Scuorzio and U.S. Pat. No. 5,456,361 to Walsh et al. The Scuorzio patent discloses a kit assembly for oral hygiene care. A first compartment contains baking soda; a second compartment receives hydrogen peroxide. The baking soda compartment serves as a repository for the mixture and a receptacle for receiving a toothbrush. The Walsh et al. patent discloses a tray with receptacles for hygienic care items and includes receptacles for rinsing contact lenses and for receiving used mouthwash.
The foregoing examples of devices for mixing ingredients are oftentimes large. Moreover, their mixing volumes are not sufficient for many of the mixtures required in medical offices.
As particularly shown in the Discko and Haynie patents, the kits in the prior art usually include a spatula. These could benefit from being disposable in the same way as the mixing bowls. However, the shape of a spatula impacts the efficiency with which ingredients mix and the optimal shape may vary from one mixture to another. The inventory of prior art disposable spatulas required stocking differently shaped spatulas. However, oftentimes personnel in a medical office elect to stock only a few reusable spatulas of each type even though it becomes necessary to disinfect these spatulas after each use.
None of the prior art discloses or suggests a mixing system in which the components are completely disposable. There remains a need for a one-piece, free-standing, disposable bowl adapted for mixing various materials and disposable spatulas for optimizing the mixing process.